The present invention relates to SAW (surface acoustic wave) substrates, and more particularly to such a substrate which is adaptable to any one signal in a multitude of signal possibilities.
SAW substrates are well known in the art. Sync and tap transducers are disposed on each SAW substrate along with positive and negative buses. Each transducer includes at least two electrodes which extend across the substrate between the busses with each electrode being connected to one of the busses. The substrates are fabricated of a piezoelectric material and have a metal clad surface on which the pattern of electrodes and busses is etched, after being deposited thereon using a mask.
Many SAW systems utilize only one signal and consequently, all of the substrates for such systems can be fabricated with a single mask. However, other SAW systems are possible wherein several different signals are utilized, such as is disclosed and claimed in my application entitled RECOGNITION TAG FOR USE IN A SYSTEM FOR IDENTIFYING DISTANT ITEMS which was filed in the USPTO on Nov. 28, 1994 and was assigned Ser. No. 08/346,594. Of course, the SAW substrate relating to each different signal would require a separate mask and consequently many different masks would be required for such systems.